The whole FAT licensing saga between Microsoft and TomTom just got a whole lot more complicated. Microsoft sued TomTom because the satnav maker had not licensed FAT from Microsoft, even though several others have. This left TomTom in a difficult position: not license it, and face legal penalties - license it, and violate the GPL. The second part, however, is up for debate now: the terms under which Microsoft licenses FAT may not violate the GPL at all. Near-instant update: On Slashdot, Bruce Perens and Jeremy Allison have explained that the FAT terms are still a GPL violation. Allison accidentally emailed the journalist who wrote this story with the wrong information.

In other words, TomTom could license FAT from Microsoft under terms that would not violate the GPL. The terms in question add a cap to royalties, which in fact does not violate the GPLv2, according to GPL experts like Eben Moglen and Jeremy Allison (Allison later had a change of heart, and now believes it is a violation, but he isn't sure). Even though these terms have mysteriously vanished from Microsoft's website, Microsoft has confirmed that the terms are still applicable.

David Kaefer, General Manager of IP Licensing at Microsoft, said: "When we announced the FAT licensing program in December 2003, we indicated that pricing would be $0.25 per unit up to a cap of $250,000 for devices that use FAT for removable memory, such as flash memory cards. At that time, we also noted that some companies may wish to negotiate broader or narrower rights than our standard license for flash memory type scenarios and that pricing may vary. Today, our public pricing approach is unchanged."

This raises two interesting questions. First, why didn't TomTom license FAT properly, without violating the GPL? Secondly, and this is maybe even the more interesting question: why didn't Microsoft point this out in the first place? It could've saved them lots of bad publicity if they did.